The overall objective of this study is to evaluate the pharmacokinetics of supplemental ascorbic acid (AA) in acutely ill, malnourished, elderly males receiving total parenteral nutrition (TPN). The specific aims of this study are as follows: (1) to evaluate the physical and nutritional status of thirty elderly male subjects who have been depleted of ascorbic acid as a result of short-term malnutrition, (2) to evaluate the pharmacokinetics of ascorbic acid in these subjects during vitamin replenishment, and (3) to determine the dose of ascorbic acid and the duration of therapy required to restore plasma and leukocyte ascorbic acid concentrations to normal. The protocol for this study includes the assessment of the physical and nutritional status of thirty males, over 65 years, with specific reference to plasma and leukocyte ascorbic acid concentrations. Prior to implementation of TPN, subjects will be randomly assigned to one of three treatment groups and ascorbic acid will be administered intravenously in conjunction with TPN at one of three daily doses (100, 500 and 1000 mg per day). Blood and urine samples will be collected daily for seven days and then weekly for up to three additional weeks. Ascorbic acid will be analyzed by high pressure liquid chromatography and its distribution and elimination characteristics will be determined. The pharmacokinetic characteristics of ascorbic acid will be evaluated in subjects before, during and after ascorbic acid supplementation. The optimum dosage and time required for ascorbic acid replenishment will be determined. The pharmacokinetics of ascorbic acid have not been studied in the elderly. While standard protocols exist for vitamin supplementation during TPN, there have been no systematic evaluations of the specific dosage and time required for ascorbic acid replenishment. It is anticipated that this pilot study will provide a foundation upon which more extensive research will be conducted in order to delineate the pharmacokinetics of ascorbic acid in the acutely ill, malnourished, elderly patient. It is also hoped that the data obtained from this study will provide a rational basis upon which recommendations for ascorbic acid supplementation during TPN in the elderly can be made.